Device for securing electric



G. HAOUR Dec. 17, 1940.

DEVICE, FOR SECURING ELECTRIC CONDUCTORS TO AN INSULATOR Filed Aug. 6,1958 2 Sheets-Sheet 1 G. HAOUR Dec. 17, 1940.

DEVICE FOR SECURING ELECTRIC CONDUCTORS TO AN INSULATOR Filed Aug. 6,1958 2 Sheets-Sheet 2 Patented Dec. 17, 1940 PATENT OFFICE DEVICE FORSECURING ELECTRIC CONDUCTORS TO AN INSULATOR Georges Haour, Alger,Algeria, assignor to Societe Algerienne dEclairage et de Force, Alger,

Algeria Application August 6, 1938, Serial No. 223,428 In France August11, 1937 5 Claims.

In the present construction of overhead electric lines, each of the twocontinuous sections of each electric wire, situated on either side of asupporting insulator, is connected with this insulator by binding. Whenthe two sections are in position, the stresses which they exert upon theinsulator are usually in equilibrium, and thus the tower or postcarrying this insulator will not be subjected practically to any lateralstress, as the resultant of the tractive forces exerted in contrarydirections by. the two sections are vertical, or practically vertical.However, such is not always the case, and chiefly if one of the sectionsshould break. The tower or post is then subjected to a great lateralstress due to the traction of the section which is not broken. Theabnormal and unsymmetrical stress to which the tower or post issubjected may be sufiicient to cause damage to the same.

The present invention has for its object a device for the removablesecuring a conductor to an insulator, by which the serious drawbackabove mentioned is obviated. The said device is chiefly characterized bythe fact that it is so constructed that in the case of an abnormalstrain upon either of the two sections situated on the respective sidesof the insulator, the connection between the said sections and theinsulator can be automatically broken, thus allowing, for the saidconductor, a longitudinal movement in the direction of the said abnormalstrain, which is no longer imparted to the insulator. The said devicecomprises a cap-piece which can be secured to the upper part of theinsulator, and comprises two cheeks which are parallel to the axis ofthe conductor, and whose upper edges comprise oblique surfaces whichsupport suitable stops secured to the conductor.

In one embodiment, the said oblique surfaces form, on each cheek of thecap-piece, a deep notch having the form of a V, in each of which isengaged an axle or journal mountedon a wireclamp which is placed uponthe conductor.

In another embodiment, the oblique surfaces of each cheek of thecap-piece form a projection having the shape of an inverted V, i. e.,with its vertex upwardly directed, and this projection is locatedbetween two axles or journals pertaining to two respective wire-clampssecured to the conductor, on which a weak point can be formed betweenthese two wire-clamps. The advantage of this weak point is that thebreakage of the conductor under an abnormal stress will take place atthis point, and hence this breakage will offer a less drawback, andchiefly for supports which are not provided with cap-pieces with slidingattaching parts. Another advantage of this weak point is that theconductors can be used over again after the breakage, if the reducedsection has been determined in such way that in their normalcross-section, the conductors have not exceeded their elastic limit.

Preferably, the lateral edges of the two cheeks of the cap-piece comenearer together towards the top, and thus in the case of breakage of oneof the sections or strands of the conductor after an abnormal strainupon this section which has brought the axles of the wire-clamp, or ofone of such clamps, against the corresponding lateral face, the secondsection can escape after such breakage of the first section.

In the accompanying drawings, which are given solely by way of example:

Fig. 1 is a side View of a device according to the invention.

Fig. 2 is a front view of the same.

Figs. 3 and 4 are two diagrams showing the advantage obtained by thelateral oblique faces of the cheeks.

Fig. 5 is a side view of a modification with inverted V-shaped parts.

Fig. 6 is a corresponding front View.

In the embodiment shown in Figs. 1 and 2, the

device comprises a cap-piece l, preferably of metal, which is secured tothe insulator 2 by sealing at 3 (it should be noted that the cap-piececan be secured to the insulator in any other manner, for instance bymeans of a collar).

The cap-piece l essentially comprises two cheeks 4 and 5 which have theparallel position and are parallel to the electric line wire. Each ofthe checks 4 and 5 forms at the top part a V-shaped notch bcd, whosepoint is downwardly directed. The V-shaped notches of the two cheekshave the opposite position. The lateral faces ab and de of each cheekare oblique, and proceed, at the top, towards the transverse plane ofsymmetry XX.

At the point adjacent the cap-piece i, the wire 6 is held in awire-clamp consisting of two jaws l and 8, which are pressed against thewire by a strap 9 which passes through a transverse block l0, and whichcarries two clamping nuts I l. The block I0 is provided at each end witha journal [2 whose axis YY is horizontal and is perpendicular to thelongitudinal axis ZZ of the wire 6.

The operation is as follows. In normal conditions, the wire clamp rests,by the ends of its journals I2, in the lower parts of the two V- shapednotches bed of the cap-piece I.

arrows f and f owing to a slight difference between the forces of.traction in opposite directions which are exerted upon the two sectionsof the wire situated on the respective sides of the wire clamp in twosuccessive spans of the electric line,

-a resistance which is sufficient to prevent the wire-clamp from leavingthe cap-piece. the case of an excessive force, and chiefly in the caseof breakage of one of the two, sections of the wire, the sides be and cdwill no longer prevent the movement of the journals l2 resulting fromthe traction of the wire which is not broken.

The sides ab and de, situated on either side of the V-shaped part, onthe checks 4 and 5 of the cap-piece l, are inclined (Figs. 2 and 4), andserve to prevent the lateral holding of the wireclamp against thecap-shaped piece I, in the case in which the wire-clamp has left theV-shaped parts bcd for any fortuitous cause and is now urged in theopposite direction.

In fact, Fig. 3 shows that if the faces a'b and de' were vertical, (thewire-clamp would become jammed at p against the cheeks if the breakageof the section mn should take place after a first displacement in thedirection of the arrow f by the action of this section and thus by thesubsequent traction of the secton no in the direction I the cap-piece Iwould be subjected, in-the direction I to a great force, which mightcause the overturning of the post or tower carrying the insulator withits cap-piece. But with the in clined faces ab and de (Fig. 4) thewire-clamp, which has now come to the point p by the action of thesection nm is enabled, after thebreakage of the said section nm, to riseunder the action 40 of the section no and may even escape at d, in

certain cases, if the traction exerted by the section no becomesexcessive.

Such effects may occur, especially with a line covered with frost, owingto the difference in the 5 traction due to the deposit of frost upon oneof the two sections (nm for instance) without break-age of the wire. Inthis case, the cap piece, will move in adireotion (arrow f for instance)contrary to that of the span no which is not 50 frosted. If the breakageof the wire shouldgthen occur on the side of the support towards whichthe cap-piece has slid (in the section nm), the

cap-piecewill be abruptly drawn in the direction of f contrary to itsfirst movement. At this 55 time, asabove stated, one of the sides (abforinstance) of the checks 4 and 5 of the cap-piece I, will enable the wireclamp to slide upon it.

Figs. 5 and 6 show a modification, in which the V-shaped notch of eachcheek 4' or 5 of the 60 cap-piece I represented in the precedingconstruction is replaced by a projecting part having the form of aninverted V; the lateral faces ab" andd"e' are oblique, as before, andare connected with the sides b'c' and c'd by two 55 horizontal parts b"band d"d, which support the journals l2 and I2 of two wire-clamps 1 8 and1 8 of the above-mentioned type, which are pressed upon the conductor 6.

It will be at once observed that in the case of 70 an abnormal strainupon one section of the wire,

'75 ing V-shaped notches, the'sides b'c' and c'd' of But in the cheeksof the'cap-piece, upon which the two wire-clamps rest by the ends 'oftheir journals, will have a suflicient slope to prevent the movement ofthe said clamps, and hence of the wire, when the longitudinal strains ofthe two sections of the wire do not exceed the normal value, and toallow this movement when such strains are abnormal. The fact which,as-to its utilization, constitutes the difference between the cap-piecewith projections having the form of an inverted V and the cap-piecehaving'V-shaped notches, is that the first of these will allow ofproviding, between. the two wire-clamps, at the point q (Fig. 6) a weakpoint in the wire 6' analogous to a mechanical fuse, thus permitting thebreakage of the wire when the stress exceeds a. given value. r

This weak point is obtained by reducing the cross-section of the wire atthis point.

Having now described my invention what I claim as new and desire tosecure by Letters Patent is:

1-. A device for attaching an electric conductor to an insulator whichcomprises a cap piece adapted to be secured to the top of the insulatorand provided with two parallel cheeks, the outline of each cheek havingat least one substantially horizontal bearing portion and on at leastone side of said bearing portion and in succession two portions inclinedin contrary directions and converging to an upper edge located higherthan said horizontal bearing portion, the; inclined'portion adjacentsaid horizontal portion merging in said horizontal portion, a pindisposed at right angles to said cheeks and resting normally on thehorizontal bearing portion of :both cheeks, clamping means adapted toreceive said electric conductor, and connecting means connecting saidclamping means to said pin, whereby said pin is adapted to slide on theinclined portion of each cheek adjacent said bearing portion and to reston the other inclined portion under an abnormal stress directed towardssaid one side of said bearing portion and to slide again successively onsaid inclined portions towards said bearing portion under another stresshaving an opposite direction to the first stress.

2. A device for attaching an electric conductor to an insulator whichcomprises a cap piece adapted to be secured to the top of the insulatorand provided with two parallel cheeks, the outline .of each cheek havingtwo substantially horizontal bearing portions at the same level and at adistance from each other and between said bearing portions two portionsinclined in contrary directions and converging to an upper edge locatedhigher than said horizontal bearing portions, each inclined portionmerging in the adjacent' horizontal bearing portion, two pins disposedat right anglesto said cheeks and resting normally on the horizontalbearing portion of both cheeks respectively on either side of saidinclined portions, two clamping means adapted to receive said electricconductor, andconnecting means connecting said two clamping meansrespectively to said two pins, whereby each pin is adapted to slide onthe adjacent inclined portion and to rest on the other inclined portionunder an abnormal stress directed towards the other pin and to slideagain on said inclined portions towards its initial position underanother stress adapted to be secured to the top of the insulator andprovided with two parallel cheeks, the outline of each cheek having twosubstantially horizontal bearing portions at the same level and at adistance from each other and on either side of each horizontal bearingportion two inclined portions merging in said horizontal bearingportion, the inclined portions adjacent one horizontal bearing portionbeing inclined in a contrary direction to that of the inclined portionsadjacent the other horizontal bearing portion and the two inclinedportions situated between said horizontal bearing portions converging toan edge located between said horizontal bearing portions, two pinsdisposed at right angles to said cheeks and resting normally on thehorizontal bearing portion of both cheeks respectively on either side ofsaid edge, two clamping means adapted to receive said electricconductor, and connecting means connecting said two clamping meansrespectively to said two pins.

4. In combination an insulator, a cap piece adapted to be secured to thetop of said insulator and provided with two parallel cheeks, the outlineof each cheek having two substantially horizontal bearing portions atthe same level and at a distance from each other and on either side ofeach horizontal bearing portion two inclined portions merging in saidhorizontal portion, the inclined portions adjacent one horizontalbearing portion being inclined in a contrary direction to that of theinclined portions adjacent the other horizontal bearing portion and thetwo inclined portions situated between said horizontal bearing portionsconverging to an edge located between said horizontal bearing portions,two pins disposed at right angles to said cheeks and resting normally onthe horizontal bearing portion of both cheeks respectively on eitherside of said edge, an electric conductor having a weak point, twoclamping means receiving said electric conductor respectively on eitherside of said Weak point, and connecting means connecting said twoclamping means respectively to said two pins.

5. A device for attaching an electric conductor to an insulator whichcomprises a cap piece adapted to be secured to the top of the insulatorand provided with two parallel cheeks, the outline of each cheek havingone substantially horizontal bearing portion and on each side of saidbearing portion and in succession two portions inclined in contrarydirections and converging to an upper edge located higher than saidhorizontal bearing portion, the inclined portions a-djacent saidhorizontal portion merging in said horizontal portion, a pin disposed atright angles to said cheeks and resting normally on the hori zontalbearing portion of both cheeks, clamping means adapted to receive saidelectric conductor, and connecting means connect'mg said clamping meansto said pin.

GEORGES HAOUR.

